The tasks of Working Groups 1 to 6 at the 4th Consensus Meeting of the Oral Reconstruction Foundation were to elucidate clinical recommendations for implant-supported full-arch rehabilitations in edentulous patients. Six systematic/ narrative reviews were prepared to address the following subtopics: (1) the influence of medical and geriatric factors on implant survival; (2) the prevalence of peri-implant diseases; (3) the influence of material selection, attachment type, interarch space, and opposing dentition; (4) different interventions for rehabilitation of the edentulous maxilla; (5) different interventions for rehabilitation of the edentulous mandible; and (6) treatment choice and decision-making in elderly patients. Consensus statements, clinical recommendations, and implications for future research were determined based on structured group discussions and plenary session approval.

Purpose: To synthesize evidence derived from systematic reviews (SRs) on different interventions for rehabilitation of the edentulous maxilla with implant-supported restorations. Materials and Methods: A protocol-oriented search was established to address the PICO question: What is the current evidence regarding rehabilitation of the edentulous maxilla with different implant-supported prostheses in terms of implant and prosthesis survival? The primary outcomes were implant and prosthesis survival rates evaluated from SRs of clinical studies including adult patients with complete edentulism of the maxilla and comparing different implant-supported rehabilitation strategies. Methodologic quality of the SRs was assessed with the AMSTAR-2 tool. Results: The final selection process led to the inclusion of 36 SRs that were grouped as: (1) addressing maxillae with sufficient bone to place implants; (2) addressing maxillae with insufficient bone to place implants; and (3) comparing different types of prosthesis, number of implants, patient-reported outcomes, and economic evaluations. The literature describes four or more implants as suitable for full-arch fixed prostheses and implant-supported overdentures; in both cases, the overall survival rate is > 95%. Miniimplants present very high short-term failure rates (> 30%). Poor description of technical complications, adjustments, and maintenance and corresponding costs precluded a cost-effectiveness analysis. Conclusion: No implant-supported rehabilitation of the edentulous maxilla (fixed or removable) should be supported on fewer than four implants. A one-piece full-arch fixed dental prosthesis can be supported by a minimum of two anterior axial plus two posterior distally tilted implants or by six to eight axial implants symmetrically distributed through the posterior and anterior regions of the arch. Four to six implants is the advised number to support an overdenture. The use of mini-implants in the maxilla is inadvisable.

The aim of this study was to evaluate long-term outcomes in a 10-year follow-up study of patients who previously completed a 3-year multicenter randomized controlled trial of immediate and early loading of dental implants with a hydrophilic and chemically active surface (SLActive) in the posterior maxilla or mandible. The patients received implants to replace at least one missing tooth, with provisional restoration on the day of surgery (immediate loading) or 28 to 34 days later (early loading). Implant survival, change in crestal bone level, and patient satisfaction were evaluated. In total, 56 patients (with 72 implants) were available after 10 years and fulfilled the criteria for the radiographic bone level evaluation. The mean crestal bone level change from implant surgery to 10 years was -2.00 ± 1.19 mm and -1.37 ± 1.06 mm in the immediate and early groups, respectively. The corresponding change between 5 to 6 months' post-surgery (permanent fixed restoration placement) and 10 years was -1.25 ± 0.99 mm and -0.89 ± 1.11 mm in the immediate and early groups. After the initial remodeling phase (5 to 6 months) where the depth of implant placement had an influence on the initial bone remodeling, no significant differences between the two treatment groups were detected. Mean implant survival was 97.6% (98.2% and 97.1% in the immediate and early loading groups, respectively). Implants with the SLActive surface show successful long-term outcomes following immediate or early loading in posterior maxillae and mandibles. Schlagwörter: crestal bone level, dental implant, early loading, immediate loading, SLActive, 10-year follow up

Background: A stable marginal bone and healthy peri-implant mucosa define the fundament for long-term stability of dental implants and both have impact on a satisfying esthetical and functional outcome. Apart from surgery, implant design and prosthetic parts have potential influence on these important outcome parameters. The CONELOG® SCREW-LINE implant by CAMLOG Biotechnologies AG offers a promising implant design with conical abutment connection and integrated platform shift. Aim: Evaluation of radiographic bone level changes from time of implant placement up to 60 months after prosthetic delivery by intraoral standardized x-rays in a prospective observational study. Secondary parameters were survival rate, performance of restorative components, nature and frequency of adverse events and the patient satisfaction. Material and Methods: Two to three implants of diameters 3.8 and 4.3 mm and lengths of 11 and 13 mm were inserted in the posterior mandible. Opposing dentition were natural teeth or fixed restorations. The implant shoulder was placed at bonelevel. Prosthetic delivery (loading) took place after 6-12 weeks in class I-III or 12-18 weeks in class IV bone. Peri-apical radiographs were taken after surgery and before and after abutment/crown placement. Routine clinical controls, photographs, and peri-apical radiographs were taken at 6, 12, 24, 36, 48 and 60 months after loading. Results: 52 implants were set in 24 patients. Mean age was 48.9 (SD ±13.8). Twenty patients received two, 4 had three neighbouring implants. Thirty-six implants in 17 patients could be followed over 60 months post loading. Seven patients (n=16 implants) dropped out during the course of the study. One patient withdrew consent, two patients died, three patients were lost to follow-up and one patient dropped out by implant failure after 16 months. Two implants got lost equivalent to a survival rate of 95.4%. Between insertion and loading mean bone loss was 0.5 mm (SD: ±0.4) and between loading and 6 months a bone gain of 0.1 mm (SD ± 0.4) was observed. A gain of 0.2 mm (SD: ±0.5) was reported after 24 months and this finding remained stable to the end of the study after 60 months: 0.2 mm (SD: ±0.6). Conclusions and clinical implications: The CONELOG® SCREW-LINE implant is safe and reliable for the partially edentulous patient in the distal mandible with a good performance regarding implant survival, esthetical outcome and bone stability over the course of the study. Schlagwörter: dental implants, platform switch, mandible

Background: The platform switching concept refers to the discrepancy between smaller diameter prosthetic abutments related to implant platform diameter. Clinically, the application of such components seems to reduce marginal bone resorption and to maintain soft tissue levels improving treatment outcomes and patient satisfaction. Up to this date the literature is sparse on long-term results deriving from well-designed randomized controlled trials evaluating the efficacy of platform switching versus platform matching. Aim: The purpose of this five-year prospective randomized multicenter study was to compare the clinical performance and peri-implants marginal bone levels of implants restored with platform switching (PS) or platform matching (PM) abutments. Materials and methods: The study enrolled adult patients missing two or more adjacent teeth in the posterior mandible mesially bounded by a natural tooth. Patients underwent open flap implant insertion and were randomly allocated to the PM or PS group, receiving the corresponding healing abutments. Loading was carried out after a healing period of 6-12 weeks (and for bone quality IV 12-18 weeks) with cemented crowns. Patients were followed annually for 5 years. Outcome measures were marginal bone level changes, implant survival and clinical parameters plaque index, sulcus bleeding index and pocket probing depth. Results: Thirty-three patients received 72 implants in the PM group and thirty-five patients received 74 implants in the PS group. Sixty patients attended the final appointment of the study, 31 had received PS components and 29 had received PM components with 65 and 63 implants respectively. Estimated mean difference in marginal bone levels of PS and PM restored implants was 0.28mm (95% CI: [0.06, 0.49], p=0.011), favouring the switching components. After 5 years the overall survival rate was 96.6% with no differences between groups (p=0.647). Conclusion: Patients requiring implant supported restorations in healed bounded or free end edentulous gaps of the mandible benefit from the use of PS prosthetic components from the surgical procedure onwards. Schlagwörter: Dental Implant, platform switching, platform matching, bone level, marginal bone loss

Implant single-unit restorations have highly predictable results in terms of osseointegration, but its aesthetic integration frequently constitutes a challenge. This pilot study aims to compare the aesthetic outcome of patients receiving one single-unit implant restoration in the aesthetic zone with zirconia and titanium abutments by means of three of the aesthetic indexes proposed in the literature (PES/WES, ICAI and CIS), in order to understand if there is a correlation between them, as well as which of the abutments has a better aesthetic outcome. The participants (n=16) were submitted to a control visit, in which photographs were taken, a radiograph was collected and information regarding clinical aspects was obtained. The photographs were analysed by 19 external observers and one of the investigators. The correlation between indexes was calculated by the use of the Cohen's k and the internal consistency of the indexes was analysed by the Cronbach's α. There is an accordance between the absolute scores of the indexes, but there is no correlation when the cut-points, that discriminate an aesthetic from an unaesthetic outcome, are employed [PES/WES vs. ICAI (k=0.13)]. Before the same case, the ICAI has a 2.25 (1.96-2.59, 95% CI) higher risk to assign an unaesthetic outcome than the PES/WES. The PES/WES index has the higher internal consistency value (Cronbach's α=0.85). The cases with zirconia abutments were assessed as being more aesthetic than the ones with titanium abutments (p Schlagwörter: aesthetics, implant single unit restoration, titanium abutments, zirconia abutments, Pink Esthetic Score (PES), White Esthetic Score (WES), Implant Crown Aesthetic Index (ICAI), Copenhagen Index Score (CIS), peri-implant soft tissue

Aims of Procedures: We intend to present a technique of reconstruction of maxillary horizontal bone defects by applying, fresh-frozen cortico-cancellous blocks allografts, from the Bone Bank, Faculty of Medicine, University of Coimbra, in the onlay technique, with the aim of implant supported prosthetic rehabilitation. Case Report: A 46-year-old female with lack of retention of the upper denture. After careful review intraoral and initially, under local anesthesia, proceeded to the exposure of the alveolar crest. The blocks were prepared, stabilized and fixed to the native bed using micro-screws. After five months, reopened to remove the screws and eight implants were placed. Six months later, the patient received an implant supported rehabilitation. Results: During the re-entry procedures, all the blocks were found to be firm in consistency, well-incorporated and vascularized, with minimal resorption, allowing the installation of eight implants. There were no post-operative complications. After twelve months, the implant-supported rehabilitation was in perfect function and none of the implants were lost. Discussion: The reconstruction with onlay bone blocks, provides better outline and resistance to implant placement. The application of fresh-frozen bone blocks allografts allowed good adaptation to the recipient site, reduced operative time, less morbidity, greater availability, security implementation and patient comfort compared to the application of autografts. Conclusion: Bone reconstruction by the application of fresh-frozen allogeneic bone blocks under local anesthesia by applying the onlay technique has been shown to be a suitable alternative to the use of autografts, in bone reconstructions at a short period of time. Schlagwörter: Bone blocks, onlay technique, bone allografts, cortico-cancellous, horizontal bone defects, recipient site.

Background: One of the greatest challenges in implant clinical trials is the correct appraisal of bone levels throughout the trial span. This poster describes a technique to produce individualized X-ray positioning devices for obtaining optimally projected intraoral radiographs of dental implants with long term stability. Materials and Methods: An X-ray positioning device was built for Gendex® Visualix® eHD sensor, using the Dentsply rinn XCP-DS® system individualized by the incorporation of the bite piece within an acrylic stent to perform successive standardized radiographs to patients. X-ray tube stabilization was achieved with polivinylsiloxane. Series of 3 radiographs were taken to each patient in different moments. Specific linear measurements as the implant diameter (mesio-distal width) and the height between consecutive threads (thread pitch) were made using the software Image J 1.46r to all radiographs to determine the reproducibility and accuracy of the procedure. Image corregistration was also performed on every pair of radiographs. Results: The intra-class correlation coefficient for the mesio-distal width was 0.964 [(0.920 - 0.986) 95% CI] (p < 0.01) and 0.990 [(0.976 - 0.996) 95% CI] (p < 0.01) for the thread pitch. Conclusion: The customized sensor holder produced images proper for radiographic examination of dental implants in different moments, allowing the reduction of radiation dose given to the patient. Schlagwörter: implant, radiovisiography, reproductibility, accuracy, corregistration

Background: The platform switching (PS) concept refers to the discrepancy between smaller diameter prosthetic abutments related to implant platform diameter and clinically seems to prevent the crestal bone loss and maintain soft tissue levels. However, it is well-known the lack of well-designed prospective randomized clinical trials evaluating the efficacy of platform switching versus platform matching (PM) placed in partially edentulous mandibles. Aim: The purpose of this five-year prospective randomized multicenter study was to assess the differences in bone level changes and success rates between CAMLOG® SCREW-LINE implants supporting single crowns in the posterior mandible restored either with PM abutments or abutments with PS. This paper presents interim results obtained up to two years. Material and methods: Patients ≥18 years old missing two or more adjacent teeth in the posterior mandible and with a natural tooth mesially to the most proximal implant site were enrolled in this study. Free end situations were allowed and opposing dentition must be natural teeth or fixed restorations. Following implant placement patients were randomized either in the group for PS or for PM restorations. 67 patients (8 of them split-mouth) with 160 implants followed-up to two years post-loading were included in this interim report. The distance from implant shoulder to first crestal bone contact, at mesial and distal side, was measured with standardized radiographs and statistical evaluation of significant changes in crestal bone levels between the two abutment types over time was performed with a two-sided t-test of means from the parallel group design. Results: The PS group showed a trend for less bone level change at two years post-loading. Conclusions: At two-years post-loading the implants restored with PS abutments appear to preserve the crestal bone more predictably than the implants restored with PM abutments. Schlagwörter: Dental Implant, Platform switching, Platform matching, bone level

Introduction: Prosthetic abutments with reduced width in relation to the implant diameter (platform switching, PS) seems to have potential to reduce crestal bone loss around dental implants. There are limited studies comparing this concept with standard abutments in the same implant system. In accordance to this, the study aimed to evaluate crestal bone level of the same implants in a definite indication restored with PS and with standard abutments (SA). Materials and Methods: In a prospective randomized international multicenter study, 68 patients were provided with 163 implants (Camlog® Screw line) and restored with PS (n=83) as well as with SA (n=80) in the posterior mandible. Indications were: ≥2 adjacent missing teeth, natural tooth mesial to proximal implant site, full opposition dentition, implants placed at least 6 weeks post extraction and no bone augmentation. Primary objective was a comparison of changes in crestal bone levels (fig. 1) between the groups. We will report the first results of the implants after 1 and 2 years. Results: After a total follow-up of 2 years, in the PS group a mean bone gain of 0.15 mm was recorded between the time of prosthesis placement and 12-months post-loading and 0.22 mm after 24-months post-loading (fig. 2). In comparison, a bone loss of 0.09 mm and 0.27 mm was measured in the SA group for the one and two-years loading period. For both time points the difference is significant (p=0.005 and 0.004; fig. 3,4 and 5). The total implant survival was 98.2%, 3 implants were lost. Discussion: the PS concept seems to be suitable in order to limit crestal resorption and to preserve peri-implant bone levels. Schlagwörter: Dental Implant, Camlog, Platform Switch, Crestal Bone Resorption, peri-implant Bone Level